Punch for nut-machines



(No Model.) A

G. Gr; MGMURTRY. PUNCH FON NUT MACHINES. No. 274,957. Y Patented .'jplv'.3,188? .4

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'kvvesses. Sweden- K ww* I@ @d whichnut-inachinein the usual way, and has an open bing, but may be formed of iron, if desired.

UNITED STATES GEORGE Gr. MCMURTRY, OF ALLEGHENY CITY, PENNSYLVANIA.

PUNCH FOR NUT-MACHINES.

SPECIFICATION forming part of Letters Patent No. 274,957, dated April 3, 1883.#

Application ined April er, ieee. (No model.)

To all whom it 'may concern.:

`Be it known that I, GEORGE. G. MCMUR- TRY, 0f Allegheny G1ty,in the county of Allegheny and State ot' Pennsylvania, have invented 'a new .and useful Improvement in Punches for Nut-Machines; and I do hereby declare the following to be a full, clear, and exact description thereof.

My invention relates to the construction of' hollow or tubular punches for punching nuts and like metallic articles; and it consists mainly in perforating the punch at intervals for its entire operative length, whereby its entire operative surface will be cooled or lubricated, as the 4case may be, and, secondarily, in` providing the punch with a separable bit or point, which facilitates the construction and repair of the tubular punch and permits the punch to be altered from a blunt to a pointed punch at will or to suit the work to be done.

To enable others skilled in the art to make and` use my invention, I will now describe it by reference to the accompanying drawings, in

Figures l and 2 are longitudinal sections of my improved punch. Fig. 3 is a view of a modified form. Fig. et shows the relative positions ofthe punch aud die-box. Figs. 5 and 6 are forms ot' caps or end pieces.

Like letters ot' reference indicate like part-s in each.

The punch a is hollow,haviug a central bore, a'. It is preferably made of steel-drawn tu- In the latter case I prefer to use refined iron. It is provided with a nnmberof perforations, a2, extending through its sides at intervals for its operative length, and the outer end is either solid steel or is iitted with a plug or cap-piece, b, which may be of any desired form, and is made of steel. In the drawings I have shown two forms, one having a blunt and the other'a pointed end, Figs.5 and 6. The plug is made with a central stem, b', which tits-inside of the bore of the punch, and a iiange, b2, which extends over the end of the tube ct, as shown in Fig. 3. This plu g constitutes the enteringend of the punch. The punch is secured in the pipe or channel, c, to which I attach by any suitable coupling a iiexible pipe, d. The pipe dis connected with a pump or other device by which a hydraulic pressure may be applied to the interior, a', ofthe punch. I do not limit myself to the use of the iiexible pipe for this purpose, as it may be done by straight tubes having a telescopicjoint, which will not interfere with the reciprocatiou of the punch.

When my improved punch is used for hot punching l force water, by means of a forcepump, elevated tank, or other head, into the cavity a', which, being under pressure, is ejected through the perforations a2, and keeps'the punch cool bothinternally and externally and equally on all sides. The water which passes through the perforations t2 is spread by the movement of the punch in a thin film over the heated iron of the nut-blank and produces better surface on the bore of the uut. It also, striking against the inner surface of the diebox e before the nut-blank is forced in or after it is discharged therefrom, washes outall scale and cinder, and thus cleanses the die-box, and so prevents the wearing ofthe punch and diebox thereby. This is a very important feature when dirty iron is used for making the nuts. By these means I am enabled -to run the machine continuously without. any stoppage for the cooling of the punch, to prevent the bending of the punch, to reduce the wear of the dies, die-box, and punch, aud to make a better nut.

Vhen the punch is used for cold punching I force oil through theperforations a2, for the purpose of lubricating it, the oil spreading upon-its external surface in the same manner as the water j ust described. The tubular form of the punch gives it greater strength, and reduces the danger of its being bent and strained under the ordinary pressure to which it is exposed.

The plug b is secured in the end of the hollow punch a by riveting, or any other Way known in the arr. f

Instead of using the cap-piece, the punch need not be bored entirely through, as in Figs. l and 2. i

I am aware that for the purposes of cooling' and preservation a tubular perforated p'nueh has heretofore been employed, and do not herein claim the saine, as the punch was only y perforated at or near its extremity to permit the escape of the heated water, Snc.; but I am not aware that the perforations have been ex IOO tended at intervals along the operative portion ofthe punch in order to lubricate the same and Wash the dirt, scale, &c., from the punch and die-box, and therefore What I claim as my invention, and desire to secure by Letters Patent, is-

1. A- hollow or tubular punch having a series of perforations at intervals throughoutits operative length, which perforations communicate with the bore of the punch, substantially as and for the purpose specified.

2. The combination, with a hollow or tubular punch, of a separable shouldered bit or punch-point, substantially as and 'for the purpose specified. r 5

3. Thecon1bination',with the tubular punch having a series of perforations at intervals throughout its operative length, of a separable shouldered bit or plug-point, substantially as and for the purpose specified.

In testimony whereof I have hereunto set my hand this 24th (lay of April, A. D. 1882.

GEORGE G. MCMURTRY.

Witnesses T. B. KEER, W. B. CORWIN. 

